Control mechanism for feeding strip stock to a helical seam pipe making machine



y 1965 w. ECKHARDT CONTROL MECHANISM FOR FEEDING STRIP STOCK TO A HELICAL SEAM PIPE MAKING MACHINE Filed Jan. 2, 1962 United States Patent O 3 192 74-9 coNTnoL MECHAbiISh i Fen manner; STRIP STGCK T A HELECAL SEAM PIPE MAK- EJG MACHENE v Wiiheizn Eckhardt, Paris, France, assignor to Driam 5.1%., Vaduz, Liechtenstein Filed Iian. 2, 1962, Ser. No. 163,577 Qiainas priority, appiication Germany, Jan. 4, 1961, D 35,198 5 Claims. (Ci. 7217) The present invention relates to the production of helical seam pipe and more particularly to a control mechanism for feeding and guiding strip stock to the forming tool or mandrel of a pipe making machine and for automatically adjusting the angular position of the forming tool or mandrel relative to the direction of feed of the strip stock toward the mandrel in the event of any deviations of the strip from its normal size or shape, for example, from the normal width of the strip.

In prior apparatus of this kind, variations in width of the strip stock which was fed to the mandrel or similar forming tool were measured either directly by measuring the width of the helical gap in the wound strip or by feeding the strip with one edge along a stationary guide and moving its other edge along a tracer. The measured results were then employed for controlling the angle of feed at either by swiveling the finished pipe relative to the fixed direction of feed of the strip stock or by adjusting the direction of feed relative to the fixed pipe axis. If the swiveling adjustment of the finished pipe was alone not sufficient for attaining the required feed angle a, the

forming tool was mounted on a turntable which was additionally adjusted.

For compensating a camber of the edges of the strip stock toward the left or right, the stock was guided between two pairs of guide jaws between which at one side of the stock a spring-loaded tracing roller was pro vided which by means of levers indicated the amount of the camber. This enabled the operator of the machine to adjust the feed angle a by changing the feeding direction of the strip stock. I

It is an object of the present invention to provide a mechanism for compensating all of the deviations of the strip stock from the required shape. According to the invention this object is attained by a new combination of elements which comprises two pairs of guide rollers which are mounted behind and at a certain distance from each other and engage with the opposite sides of the strip stock while the latter is being fed toward the forming tool of the machine, and which consist of two rollers which are mounted in a fixed position at a certain dis tance behind each other at one side of the stock, and two rollers which are resiliently mounted at the other side, and a further spring-loaded tracing roller which is mounted between the fixed rollers. In accordance with the angle between the axis of the finished pipe in the pipe forming machine and the direction of feed of the strip stock which may vary with the actual shape thereof, at least one of the resiliently mounted rollers of the two pairs of rollers then serves for producing electric control impulses which occur in accordance with the width of the strip stock, while the spring-loaded tracing roller effects the impulses which are responsive to the lateral camber of the strip stock.

If the strip stock is fed to the forming tool in a manner so that one of its longitudinal edges is straight, and if the width of the strip then increases or the angle of feed of the strip decreases relative to the forming tool because the other longitudinal edge curves, the angle of feed will be automatically increased. If, however, the width of the strip which is being fed decreases or if the strip Fatented July 6, 1965 curves toward the opposite side, the feed angle will be automatically reduced. The diameter of the tubular body to be formed and the gap between the longitudinal edges to be welded together will then remain absolutely constant.

The objects, features, and advantages of the present invention will become more clearly apparent from the following detailed description thereof, which is to be read with reference to the accompanying diagrammatic drawing which shows a plan view of the mechanism according to the invention, in which the rollers guide a strip which either changes in width but has straight longitudinal edges, as indicated in full lines, or the longitudinal edges of which are curved toward the left, as indicated in dotted lines.

In the drawing, it is assumed that the strip which is to be helically bent is fed in the direction of the arrow 2 toward a forming tool or mandrel 15 of a semi-cylindrical cross section which is mounted on a turntable 16. Immediately in front of the mandrel, as seen in the direc tion of feed of strip 1, a roller 3 is mounted in a fixed position in a bearing block 4 for guiding the right longitudinal edge 5 of strip 1. Directly opposite to roller 3, a second roller 6 is mounted for guiding the left edge 14 of strip 1. This second roller 6 is adapted to yield against the action of a spring 7 in a direction transverse to the direction of feed 2. S ring 7, which preferably consists of one or more plate springs is made of a strength so that roller 6 will be in guiding engagement with strip 1 even though the latter changes in width. A further roller 8 for guiding the right edge 5 of strip 1 is likewise mounted in a fixed position at a suitable distance from roller 3 in a bearing block 9, and directly opposite to it a fourth roller 11 is mounted which is acted upon by a spring 10 and serves the same function as roller 6, namely, to guide the left edge 14 of strip 1. Between the two fixed rollers 3 and 8 and preferably at equal distances therefrom, a further roller 13 is mounted which is acted upon by a spring 12. Suitable driving means, indicated diagrammatically and designated by reference numerals 3', 6', 8' and 11', are further provided for driving at least the opposite rollers 3, 6 and 8, 11.

Assuming first that strip 1, which is secured against buckling in a conventional manner, for example, by guide plates, is fed between rollers 3, 6, 8, 11, and 13 so that its longtiudinal edges extend in a straight direction, but that the width of the strip changes, springs 7 and 10 of rollers 6 and 11 will then be compressed and the com pressive force, for example, of 500 kg, which is exerted by these rollers upon the strip will increase with the result that the left longitudinal edge 14 of strip 1 will be upset and the width of the strip will thus be reduced to a certain extent. The displacement of the axes of rollers 6 and 11 in a direction transverse to the direction of feed 2 may be employed for increasing the angle of feed of strip 1 so that the turntable 16 on which mandrel 15 is mounted will be swiveled accordingly. Thus, the diameter of the finished tubular body will remain the same even though the strip changes in width.

If due to the fact that the strip varies in thickness, the longitudinal edges 5 and 14 of the strip are curved, for example, toward the left, as indicated in the drawing in dotted lines, roller 13 will be shifted toward the right against the action of spring 12 and, due to the change in position of the axis of roller 13, the angle of feed a of strip 1 relative to mandrel 15 will be increased.

If the edges 5 and 14 of the strip are, however, curved in the direction opposite to the curvature as indicated in dotted lines, the spring-loaded roller 13 will shift from its central position toward the left, whereby the angle of feed a of strip 1 relative to mandrel 15 is reduced.

The adjustment of turntable 16 carrying the mandrel 15 in accordance with any changes in the position of the spring-loaded rollers may be effected by means of electric control elements 19 and 19' which are acted upon by the two rollers 13 and 11, respectively, and, in turn, act through electric control lines-21 upon a reversing switch 20 which is connected through lines 22, for example, to a geared motor 19 to start the same in one or the other direction so as to swivel the turntable 16 with the mandrel 15 thereon by means of a threaded spindle 18 to change the forming angle Although my invention has been illustrated and de-,

scribed with reference to the preferred embodiments thereof, I Wish to have it understood that it is in no way limited to the details of such'embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim 1'. A mechanism for automatically adjusting and controlling the angular position of a forming tool of a pipe making machine relative to the direction of feed of the strip stock to he formed into' a helical seam pipe comprising a pair of rollers rotatably mounted in a fixed position behind and spaced from each other and adapted to engage with one longitudinal edge of the strip stock, a second pair of rollers rotatably mounted opposite to said fixed rollers and yieldabletransversely to said direction of feed and adapted to engage resiliently with the other longitudinal edge of said strip stock, a fifth roller rotatably mounted intermediate said fixed rollers and also yieldable transversely to said direction of feed and adapted to engage resiliently with said first edge, resilient pressure means acting upon said yieldable rollers, and electric control means responsive tothe transverse. movements of said fifth roller and of at least one of said second pair of rollers for adjusting and controlling the angular position of said forming tool relative to said direction of feed in accordance with any deviations in shape of said strip stock.

2. A mechanism according to claim 1, further comprising means including said second pair of rollers for upsetting said other longitudinal edge of said strip stock in response to width deviations of said stock such as to increase the Width of said stock.

3. A mechanism according to claim 2, wherein said means for upsetting comprises spring means including springs urging said second pair of rollers against said other longitudinal edge.

4. A mechanism according to claim 1, wherein means are provided for driving said first-named pair of rollers and said second pair of rollers.

5. A mechanism for automatically adjusting and controlling the angular position of. a forming tool of a pipe making machine relative to the direction of feed of the strip stock to be formed into a helical seam pipe comprising a turntable, said forming tool being mounted on said turntable, motondriven means for swiveling said turntable with said forming tool thereon relative to said direction of feed, a pair of rollers rotatably mounted in a fixed position behind and spaced from each other and drivingly engaging one longitudinal edge of the strip stock, means for driving said pair of rollers, a second pair of rollers rotatably mounted opposite to said fixed rollers and yieldable transversely to said direction of feed and resiliently drivingly engaging the other longitudinal edge of said strip stock, means for driving said second pair of rollers, a fifth roller rotatably mounted intermediate said fixed rollers and also yieldable transversely to said direction of feed and adapted to engage resiliently with said first edge, resilient pressure means acting upon said yieldable rollers, and electric control means responsive to the'transverse movements of said fifth roller and at least one of said second pair of rollers for controlling the operation of said motor-driven means so as to adjust and control the angular position of said forming tool relative to said direction of feed in accordance with any deviations in shape of said strip stock, the transverse movements of said roller of said second pair being controlled by changes in width of said strip stock, and the transverse movements of said fifth roller being controlled by a camber of said strip stock.

References Cited by the Examiner UNITED STATES PATENTS 3,019,834 2/62, Montignot Q 113-3s 3,030,488 4/62 Kuckens 113 3s FOREIGN PATENTS 1,118,128 11/61 Germany. 1,118,129 11/61 Germany.

853,673 11/60 Great Britain.

CHARLES W. LANHAM, Primary Examiner. NEDWIN BERGER, Examiner. 

1. A MECHANISM FOR AUTOMATICALLY ADJUSTING AND CONTROLING THE ANGULAR POSITION OF A FORMING TOOL OF A PIPE MAKING MACHINE RELATIVE TO THE DIRECTION OF FEED OF THE STRIP STOCK TO BE FORMED INTO A HELICAL SEAM PIPE COMPRISING A PAIR OF ROLLERS ROTATABLY MOUNTED IN A FIXED POSITION BEHIND AND SPACED FROM EACH OF OTHER AND ADAPTED TO ENGAGE WITH ONE LONGITUDINAL EDGE OF THE STRIP STOCK, A SECOND PAIR OF ROLLERS ROTATABLY MOUNTED OPPOSITE TO SAID FIXED ROLLERS AND YIELDABLE TRANSVERSELY TO SAID DIRECTION OF FEED AND ADAPTED TO ENGAGE RESILITNELY WITH THE OTHER LONGITUDINAL EDGE OF SAID STRIP STOCK, A FIFTH ROLLER ROTATABLY MOUNTED INTERMEDIATE SAID FIXED ROLLERS AND ALSO YIELDABLE TRANSVERSELY TO SAID DIRECTION OF FEED AND ADAPTED TO ENGAGE RESILIENTLYU WITH SAID FIRST EDGE, RESILIENT PRESSURE MEANS ACTING UPON SAID YIELDABLE ROLLERS, AND ELECTRIC CONTROL MEANS RESPONSIVE TO THE TRANSVERSE MOVEMENTS OF SAID FIFTH ROLLER AND OF AT LEAST ONE OF SAID SECOND PAIR OF ROLLERS FOR ADJUSTING AND CONTROLLING THE ANGULAR POSITION OF SAID FORMING TOOL RELATIVE TO SAID DIRECTION OF FEED IN ACCORDANCE WITH ANY DEVIATIONS SHAPE OF SAID STRIP STOCK. 